6 votes

UP - South Street Arch


West Face

The bridge was originally built by the Chicago, St. Paul and Fond du Lac Railroad, later acquired by the Chicago & Northwestern. It appears that the bridge was widened in 1897 to accomodate a second track.

Photo taken by J.R. Manning in July 2010


BH Photo #169880

Street View 


Rare Heliocoidal (or "spiral") Arch, built in 1867 and widened in 1897 for a second track by the C&NW.


Stone arch bridge over South Street on Union Pacific Railroad
Woodstock, McHenry County, Illinois
Open to traffic
Built 1867, Widened 1897
- Chicago & North Western Railway (CNW)
- Chicago, St. Paul & Fond du Lac Railroad (CStP&FdL)
- Union Pacific Railroad (UP)
Rare Heliocoidal (or "spiral") Arch, built in 1867 by the Chicago, St. Paul and Fond du Lac Railroad, later aquired by the Chicago & Northwestern, which was acquired by the UPRR in 1995.
Span length: 16.0 ft.
Total length: 16.0 ft.
Approximate latitude, longitude
+42.31285, -88.44350   (decimal degrees)
42°18'46" N, 88°26'37" W   (degrees°minutes'seconds")
Approximate UTM coordinates
16/381038/4685521 (zone/easting/northing)
Quadrangle map:
Inventory number
BH 45671 (Bridgehunter.com ID)

Update Log 

  • November 4, 2021: New photo from Geoff Hubbs
  • July 16, 2018: New photos from John Marvig
  • May 8, 2015: Updated by Luke: Added category "Helicoidal Arch"
  • October 9, 2013: New Street View added by J.P.
  • September 16, 2012: Updated by Luke Harden: Added categories "Union Pacific Railroad", "Chicago & North Western Railway"
  • July 18, 2010: Added by J.R. Manning


  • J.R. Manning - thekitchenguy [at] sbcglobal [dot] net
  • J.P. - wildcatjon2000 [at] gmail [dot] com
  • John Marvig - marvigj27 [at] gmail [dot] com
  • Geoff Hubbs


South Street Arch
Posted July 19, 2010, by Matthew Lohry (matthewlohry [at] yahoo [dot] com)

The 7th Street Improvement Arches in St. Paul, MN, also uses this helicoidal arch design. This bridge has two spans rather than one.

South Street Arch
Posted July 18, 2010, by J.R. Manning (thekitchenguy [at] sbcglobal [dot] net)

I found this gem in Woodstock, Illinois while I was looking for something else. Note the heliocoidal arch construction - I've never seen anything like this before.